Attn Java Gurus

[james182]

If I have an object that I have created, (the object has a HashMap and a map that extends HashMap as its two fields)
how do I save this object to a file and then open the program at another time and load that object from the file?

 

[jonmullen]

this should help you Text

 

[MrScott81]

use an ObjectOutputStream to write your object to a file....then use an ObjectInputStream to read it in, simple as that 🙂

HTH

 

[Daishiki]

Originally posted by: jonmullen
this should help you Text

fine...
import java.io.*;
class theObject implements Serializable
...
try{
ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(filename));
out.writeObject(the object);
}
catch(IOException e) { blah blah }
try {
ObjectInputStream in = new ObjectInputStream(new FileInputStream(filename));
theObject object = (theObject)in.readObject(); //load in the object and cast it
}
catch(IOException e) { blah blah }

 

[james182]

This is what I have for my code and its not working. Does anyone see anything wrong with this:
String fn=JOptionPane.showInputDialog("Please enter the name that you wish to save the database as.");
File file=new File(fn);
try{
file.createNewFile();
} catch (Exception e){
JOptionPane.showMessageDialog(null, e);
}
try{
oos = new ObjectOutputStream(new FileOutputStream(file));
oos.writeObject(cdc);
} catch(Exception e){
JOptionPane.showMessageDialog(null, e);
}
try{
oos.close();
} catch (Exception e){
JOptionPane.showMessageDialog(null, e);
}
}

 

[mundane]

Where / how do you declare oos and cdc? And make sure that your class implements java.io.Serializable, if you want to write it to a stream.

-Josh

 

[Daishiki]

does it not compile, or not work properly?